Phosphorus oxybromide → 4-bromo-1H-pyrazolo[4,3-c]pyridin-3-amine

Participants

Reaction Conditions

Reaction Steps

To 3.5 g of POBr3 melted at 45° C. is added 0.4 g of 3-amino-1H-pyrazolo[4,3-c]pyrid-4-ol, and the suspension is then maintained at 70° C. for 4 hours. The resulting mixture is allowed to cool and is hydrolysed, cautiously, with sodium bicarbonate solution. The mixture is extracted with ethyl acetate. The organic phase is isolated and dried over magnesium sulfate, filtered and then concentrated under reduced pressure. 0.33 g of 4-bromo-1H-pyrazolo[4,3-c]pyrid-3-ylamine is obtained in the form of a cream-coloured solid.

Provenance & Evidence